The present invention relates to a mechanical locking device including a rotatable stem-shaped locking member for latching together a first part having a locking opening therein and a second part, by cooperation of said locking member with said opening during a rotation of said locking member.
Such a device is already known from page 40 of "Machine Design", Sept. 25, 1980. Therein the locking member is a partly cylindrical rod having a rounded part and a flat part; the first part is a rack for mounting electrical equipment and provided with a longitudinal U-shaped guiding channel laterally delimited by a fixed flange and a flexible lip, and with a cylindrical locking channel extending along the flexible lip; the second part is a printed circuit board with an edge slidably mounted in the guiding channel; and the rod is housed in the locking channel. When its flat part faces the flexible lip, the rod can be easily inserted in the locking channel and when it is then turned until its flat part is substantially perpendicular to the flexible lip the latter is pushed into the direction of the fixed flange so as to lock the printed circuit board.
An advantage of this known device is that the printed circuit board is locked by a simple rotation of the rod and without axial displacement thereof so that no axial forces are hereby exerted on the board. Such forces could be harmful for the printed circuit board and/or for the connectors by means of which the board is coupled to the rack electrical equipment. However, with this known device the locking channel and the rod extend over the whole length of the printed circuit board and it is essential to provide a flexible lip extending over this whole length.